The presence of specific CD8
+ T cells capable of in vitro proliferation in response to a specific ASFV strain correlates with in vivo protection. Detection of ASFV-specific CD4+, double positive CD4+/CD8low or CD8high proliferating T-cells of E75CV1-inoculated pigs at day 28 pi, just before ASFV-virulent challenge. The specific proliferation was performed by labeling the PBMCs with CFSE followed by in vitro stimulation with either E75 or BA71 ASFV strains as stimuli. PBMCs were finally stained with anti-CD4 or anti-CD8 antibodies and analysed by flow cytometry. The percentage of specific CD4+, double positive CD4+/CD8low and CD8high proliferating T-cells is also shown.